<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>effective-2</title>
    <link rel="stylesheet" href="./css/effective_html_tag.css">
</head>

<body>
<h2>画一个有边缘色的三角形</h2>
<div class="chat-msg">h1，亲</div>
</body>

</html>